Find information on thousands of medical conditions and prescription drugs.

Epilepsy

This article is about epilepsy in humans. For information on epilepsy in other animals, see Epilepsy in animals. more...

Home
Diseases
A
B
C
D
E
Ebola hemorrhagic fever
Ebstein's anomaly
Eclampsia
Ectodermal Dysplasia
Ectopic pregnancy
Ectrodactyly
Edwards syndrome
Ehlers-Danlos syndrome
Ehrlichiosis
Eisoptrophobia
Elective mutism
Electrophobia
Elephantiasis
Ellis-Van Creveld syndrome
Emetophobia
Emphysema
Encephalitis
Encephalitis lethargica
Encephalocele
Encephalomyelitis
Encephalomyelitis, Myalgic
Endocarditis
Endocarditis, infective
Endometriosis
Endomyocardial fibrosis
Enetophobia
Enterobiasis
Eosinophilia-myalgia...
Eosinophilic fasciitis
Eosophobia
Ependymoma
Epicondylitis
Epidermolysis bullosa
Epidermolytic hyperkeratosis
Epididymitis
Epilepsy
Epiphyseal stippling...
Epistaxiophobia
EPP (erythropoietic...
Epstein barr virus...
Equinophobia
Ergophobia
Erysipelas
Erythema multiforme
Erythermalgia
Erythroblastopenia
Erythromelalgia
Erythroplakia
Erythropoietic...
Esophageal atresia
Esophageal varices
Esotropia
Essential hypertension
Essential thrombocythemia
Essential thrombocytopenia
Essential thrombocytosis
Euphobia
Evan's syndrome
Ewing's Sarcoma
Exencephaly
Exophthalmos
Exostoses
Exploding head syndrome
Hereditary Multiple...
Hereditary Multiple...
Hereditary Multiple...
Hereditary Multiple...
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Medicines

Epilepsy (often referred to as a seizure disorder) is a chronic neurological condition characterized by recurrent unprovoked seizures. The condition is named from the Greek epilepsis ("to take a firm grip on"). It is commonly controlled with medication, although surgical methods are used as well.

Diagnosis

The diagnosis of epilepsy requires the presence of recurrent, unprovoked seizures; accordingly, it is usually made based on the medical history. EEG, brain MRI, SPECT, PET, and magnetoencephalography may be useful to discover an etiology for the epilepsy, discover the affected brain region, or classify the epileptic syndrome, but these studies are not useful in making the initial diagnosis.

Long-term video-EEG monitoring for epilepsy is the gold standard for diagnosis, but it is not routinely employed owing to its high cost and inconvenience. It is, however, sometimes used to distinguish psychogenic non-epileptic seizures from epilepsy.

Convulsive or other seizure-like activity, non-epileptic in origin, can be observed in many other medical conditions, including:

  • psychogenic non-epileptic seizures (often wrongly called "pseudoseizures")
  • tics
  • syncope (fainting)
  • narcolepsy
  • cataplexy
  • parasomnias
  • breath-holding spells of childhood
  • non-epileptic myoclonus
  • hypoglycemia and associated neuroglycopenia
  • opsoclonus
  • hyperekplexia
  • paroxysmal kinesiogenic dyskinesia
  • infantile gratification / masturbation (onanism)
  • repetitive behaviors

Neurologists are often called upon to distinguish among the above diagnoses and epilepsy.

Epilepsies are classified five ways:

  1. By their first cause (or etiology).
  2. By the observable manifestations of the seizures, known as "semiology."
  3. By the location in the brain where the seizures originate.
  4. As a part of discrete, identifiable medical syndromes.
  5. By the event that triggers the seizures, as in primary reading epilepsy.

Causes

All the causes (or etiologies) of epilepsy are not known, but many predisposing factors have been identified, including brain damage resulting from malformations of brain development, head trauma, neurosurgical operations, other penetrating wounds of the brain, brain tumor, high fever, bacterial or viral encephalitis, stroke, intoxication, or acute or inborn disturbances of metabolism. Hereditary or genetic factors also play a role.

Seizures may occur in any person under certain circumstances, including acute illness and drug overdoses, but these provoked seizures are not part of the definition of epilepsy. Epilepsy connotes that an individual has unprovoked seizures which recur over time. In about 50% of all cases, there is no cause for epilepsy that is currently detectable even with state of the art investigations. In about 50% of cases, evidence of a brain injury, scar or malformation is found, to which the epilepsy is attributed. In many, but not all cases, abnormal electrical activity can be detected in the brain with an electroencephalogram (EEG), either during or in between seizures.

Read more at Wikipedia.org


[List your site here Free!]


Does sleep spindle frequency and density discriminate between the various types of epilepsy?
From CHEST, 10/1/05 by Juliana C. Rajter

PURPOSE: During stage 2 sleep the thalamic reticular neurons release GABA, allowing sleep spindles to emerge at an oscillatory frequency of 12-14 Hz. There is evidence from from thalamic kindling in cats that spindle oscillations develop into seizures in corticothalamic systems. From computer modeling it is hypothesized that that there is cortical transformation of one of every 2 or more spindle waves to a spike component of spike and wave discharges and the other replaced by a slow wave1. This model predicts the evolvement of spindle waves to seizures. We pondered on the predictive relationship between spindle characteristics among different types of epilepsy and compared them to subjects without epilepsy.

METHODS: 7 patients, each, with temporal lobe epilepsy, frontal lobe epilepsy, primary generalized epilepsy and 5 subjects without epilepsy were studied after IRB approval. At the time of EEG recordings 4 out of 5 normals were on benzodiazepines while the rest were on antiepileptic medications. From the whole night EEG recordings, segments of 300 seconds were extracted to assess spindle duration, number of spindles and fraction of spindle time per Epoch of stage 2 sleep by 2 independent scorers blinded to the clinical information. A 2 way ANOVA was used to test the differences between the various frequency categories.

RESULTS: See attached table.

CONCLUSION: 1.More spindles were seen in normal subjects. This represents medication effect on sleep.2. Although mean spindle duration and fraction of spindle time per epoch of stage 2 sleep occurred more in temporal lobe epilepsy, this was not statistically significant. 3.Overall spindle characteristics are not discriminative between the various types of epilepsy.

CLINICAL IMPLICATIONS: In studying patients with epilepsy in the sleep laboratory, the morphology of spindles is unlikely to offer clues to assess either the origin or activity of spike and wave discharges.1. Traub RD, Contreras D et al. Single- column thalmocortical network model exhihiting gamma oscillations, sleep spindles and epileptogenic bursts. J Neurophysiol. 2005; 93:2194-232.

DISCLOSURE: Juliana Rajter, None.

Juliana c. Rajter MD * Sigmund G. Jenssen MD Han C. Ryoo PhD Siva K. Ramachandran MD Drexel University College of Medicine, Philadelphia, PA

COPYRIGHT 2005 American College of Chest Physicians
COPYRIGHT 2005 Gale Group

Return to Epilepsy
Home Contact Resources Exchange Links ebay